Priority is claimed with respect to Application No. 00810278.2 filed in Germany on Mar. 31, 2000, the disclosure of which is incorporated herein by reference.
The invention relates to a method for gluing a cover paper to the back of a book block formed from bound printed sheets, during the production of books, brochures, magazines or the like. In the process, the cover paper is respectively supplied for the gluing with the inside facing the back of the book block and is subsequently pressed against the book block back as well as the side flanks of the book block back.
This operation is described in, among other things, xe2x80x9cTECHNOLOGIE DER KLEBEBINDUNGxe2x80x9d [Glue-Binding Technology] by Alfred Furler, Issue 1971, in Section 8.6 xe2x80x9cEINHxc3x84NGEN IN UMSCHLxc3x84GExe2x80x9d [Cover Paper Casing].
During the operation, it can happen that the cover papers are coated on the surface with a coating that is incompatible with the glue, so that the joining of cover paper and book block is unsatisfactory. Frequently, the surface is too smooth and results in an insufficient adhesion of the cover paper to the back of the book block.
A chemical process that may occur between the glue and the cover paper surface also inhibits a joining of the book block and the cover paper. Thick cover papers have a negative effect on the opening-up behavior of a book block in the book back region because they increase the unpopular clamping effect on the back.
It is an object of the invention to provide a method of the type first mentioned above that overcomes the foregoing disadvantages allows for producing a softer and more flexible book back.
The above and other objects are accomplished according to the invention by the provision of a method for gluing a cover paper to a back of a book block having side flanks adjacent the back of the book block, including the steps of: forming the book block from bound printed sheets; supplying a cover paper having one side facing the back of the book block for joining to the book block; reducing a thickness of the cover paper by forming a recess on the one side facing the back of the book block at least across a width of the cover paper corresponding to a width of the back of the book block; and subsequently pressing the cover paper to the back of the book block and to the side flanks of book block.
With this method, it is possible to create a book back that is gentler during use and makes allowances for the opening and use of a bound book, as well as makes it possible to achieve optimum compatibility between glue and cover paper.
The resulting back area, which is relieved of stresses, has a positive effect on the resilience and endurance of a book back during the opening and closing of a book.
Also, the cover papers can be prepared off-line or can be processed accordingly after leaving a cover paper feeder or while on the conveyance path to the book block back.
The cover paper material is advantageously removed in layers, at least over the width of the book block back, so that a normal surface remains.
The cover paper material is preferably removed mechanically or chemically, in a manner known to those skilled in the art.
The exposed surface can be reworked or reprocessed to optimize the glue connection between book block and cover paper.
The scooping out of the recess on the cover paper can occur before or after decorative grooves are produced on the outside of the cover paper.
The operation according to the invention can be carried out in a glue-binding apparatus.
The invention is explained in the following with the aid of an exemplary embodiment and by referring to the drawing, which may be referred to for all details not explained further in the description.